Questar telescope for sale craigslist11/24/2023 ![]() This was first offered for sale in May 1956. A 3.5" Field Model Questar, which is just the optical tube.The 3.5" Standard model, with nonremoveable optical tube and control box, the predominant model.The Questar 3.5” has been sold in variants including: Later models accept standard slide-in 1.25" eyepieces and other accessories. The Questar of the 1950s and early 1960s had a proprietary screw in eyepiece design and offered little capacity to employ third-party accessories. The ads focused on the telescope's mechanical and optical design, educational value for children, ease of use, and adaptations as a spotting scope and telephoto lens. The Questar 3.5” entered commercial production in 1954 with ads for the model run in many astronomy, science, photography, and nature related magazines such as National Geographic, Scientific American and Sky & Telescope. The design was originally envisioned as a 5-inch (130 mm) telescope, but it was decided a telescope of that size would not fit the market they were aiming for, since it would be too heavy and expensive. In the mid-1960s the patent issue was settled, and Questar’s Maksutov-Cassegrains after that time use the Gregory design with the aluminized spot on the inside of the corrector (R2). To avoid a conflict with a design patent held by John Gregory licensed to PerkinElmer, Braymer put the secondary spot on the outer (R1) surface of the corrector lens. ![]() It also included a star chart engraved in white on a blue aluminum sleeve (this doubles as a dewcap), around the barrel which contained a moon map. The cast-aluminum double-fork arm mount was designed with a built-in clock drive and became equatorial by adding the collapsible legs included. A knob for focus and another to switch in and out a magnification-doubling Barlow lens rounded out the controls. This also allowed a camera or other device to access the focal plane through a hole on the back of the Control Box. Braymer designed a built-in “Control Box” that allowed the user, looking through the main eyepiece, to switch between the main telescope and a coaxial finderscope via moving a diagonal out of the way with a flick of a knob. Braymer used a modified Cassegrain design that added an aluminized spot to the Maksutov corrector plate, creating a compact folded light path (this design is sometimes called a "Spot-Maksutov"). ![]() He used a catadioptric Maksutov design, named after its inventor Dmitry Maksutov, for the optical tube assembly. Braymer’s basic concept for the telescope was one of portability, compactness, and ease of use. In development since 1946, the Questar 3-1/2 has been the company's most notable product. The Questar 3-1/2” Maksutov Cassegrain Questar Standard 3 ½” The earliest Questars used optics produced in part by Cave Optical, but for most of their history the optics were produced by Cumberland Optical. ![]() Questar does not produce their own optics. They are used in astronomy, nature study, radar calibration/ boresighting/tracking rocket launches, surveillance, and as long-distance microscopes. For a while they also offered 12-inch (300 mm)-aperture optical-tube assemblies. Products sold by Questar include 3.5” (89 mm) and 7” (178 mm) aperture Maksutov Cassegrain astronomical/terrestrial telescopes for the consumer market. Questar produces telescopes for consumer, military, police, security, aerospace, and industrial applications. Questars have been associated with many well-known scientists and other personalities for example, in 1959, Wernher Von Braun purchased a telescope manufactured by the company. The Questar Standard telescope has been in production since 1954. Questar was founded in 1950 by Lawrence Braymer, who set up Questar to develop and market Maksutov telescopes and other optical devices for the consumer, industrial, and government customers. Its telescopes produced for the consumer market are sold under the brand name "Questar". It manufactures precision optical devices for consumer, industrial, aerospace, and military markets. Questar Corporation is a company based in New Hope, Pennsylvania. ![]()
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